/// 收据类型
class PreferableReceiptType {
  final String value;
  
  const PreferableReceiptType._(this.value);
  
  static const EMAIL = PreferableReceiptType._('EMAIL');
  static const PHONE = PreferableReceiptType._('PHONE');
  static const QR = PreferableReceiptType._('QR');
  static const PRINT = PreferableReceiptType._('PRINT');
  
  // 所有可能值
  static const values = [EMAIL, PHONE, QR, PRINT];
}